Double-storey extensions across Clacton-on-Sea
From the first sketch to final sign-off, we plan and build double-storey extensions in Clacton-on-Sea and the surrounding Essex area.
- Guide price in Clacton-on-SeaFrom £40,000 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsCO15, CO16
Guide prices for Clacton-on-Sea
Labour and material costs vary across the UK, so for Clacton-on-Sea we use our East of England factor (×1.06). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Clacton-on-Sea: £1,640 to £3,180 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £40,000 – £48,500 | £45,500 – £60,000 | £58,500 – £76,500 |
| 4 m × 4 m, two floors 32 m² | £52,500 – £63,000 | £61,000 – £80,000 | £78,000 – £102,000 |
| 4 m × 6 m, two floors 48 m² | £78,500 – £94,500 | £91,500 – £120,000 | £117,000 – £153,000 |
For a figure based on your own dimensions, use our guide-price tool.
Will the council need to approve it?
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
What is included
- Householder planning application where needed
- Breaking through at both levels, stairs and landing changes where needed
- Building regulations drawings and structural design
- Measured survey, design and planning drawings
- Ground and first floor structure, roof tied into the existing roof
- Foundations sized for two floors
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
Extensions in and around Clacton-on-Sea
We cover Clacton-on-Sea and the postcode districts CO15, CO16. We also work in nearby Harwich (12 miles), Colchester (13 miles), Maldon (21 miles), Witham (22 miles).
Just over the Suffolk border, Felixstowe is about 15 miles away. The East of England mixes market-town terraces, inter-war semis and modern estates. Clay soils are common in parts of the region, which can affect foundation design.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Double-storey extension questions answered
Do you cover all of Clacton-on-Sea?
Yes. We cover Clacton-on-Sea and the surrounding parts of Essex. Site visits are free and there is no obligation.
Who do I contract with for a double-storey extension in Clacton-on-Sea?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does a double-storey extension take to build in Clacton-on-Sea?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,640 to £3,180 per m² of new floor area including VAT, compared with £1,860 to £3,600 per m² for single-storey work, because the foundations and roof are shared across two floors.
Do I need a Party Wall Agreement?
If you are in England or Wales and the work involves a shared wall or digging foundations close to a neighbour, the Party Wall etc. Act 1996 applies and notices must be served before work starts. We tell you which notices are needed.
Book a free site visit in Clacton-on-Sea
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.